1. Field of the Invention:
This Invention pertains to fluid material measuring and dispensing, to the packaging art, and more particularly to condiment-type material packaging apparatus and methods for packaging individual serving type packages of, for example, sugar, salt, pepper, mustard, catsup, and the like.
2. Description of the Prior Art:
U.S. Pat. Nos. 2,653,430, 2,746,223, and 3,344,576 are cited as being merely representative of what is otherwise a voluminous prior art. The prior art apparatus generally is complex, requires substantial space and does not meet the increasing high productivity requirement. It has been proposed as seen in U.S. Pat. No. 3,344,576 to rotate plural material guides, i.e., funnels, which guide the material to the packets while being filled. It has also been proposed to rotate the packets themselves to facilitate filling. One also finds in the prior art various cam actuated operators which sit on the packets and which revolve and assist in the filling, metering or discharge functions which are inherent in any packaging apparatus. Metering is normally accomplished by stationary and relatively complex metering traps.
U.S. Pat. No. 3,578,778 teaches employment of a rotating filling wheel or drum having a plurality of cam actuated trap chambers or traps mounted on the drum periphery and which drum holds the material to be packaged. Each trap fills with material, isolates one or more units of material and discharges material units into synchronized individual packets or containers to be filled. While a marked advance over the prior art, the trap operations have required many moving parts.
U.S. Pat. No. 3,631,903, over which this invention marks an improvement, resides around the concept of maintaining a supply of fluid material to be packaged in a rotatable drum, rotating the drum at some uniform speed in a constant direction, and simultaneously rotating a set of "traps", i.e., metering devices or trap chambers, which are arranged in a circular configuration and which are connected to and which rotate with the drum. Each trap provides an elongated, non-linear, material flow path between an inlet and outlet and in the embodiments disclosed in the patent such path is of helical shape. At a filling station each trap is positioned so that the material to be packaged is drawn from the drum through the trap inlet and so as to locate itself at one end of the helical path. As the valve rotates around the drum axis all material in excess of a unit of material is discharged through the inlet and the rotation causes the unit to move along the helical path and approach the trap outlet. As the trap reaches a separate discharge station, the unit of material reaches the end of its helical path and is discharged in synchronism with a packet or other container to be filled, mating with the trap outlet. Two or more such helical paths and two or more units of material may be discharged simultaneously.
While the packaging apparatus and method described in U.S. Pat. No. 3,631,903 represented a dramatic improvement over the apparatus described in U.S. Pat. No. 3,578,778 and other prior packaging apparatus and methods, use of such apparatus and methods have revealed the need for even further improvements. Specifically, there has developed a need for substantially reducing the length of the run of the packaging paper between the point where the paper leaves the roll supply and the point where the filled paper is cut into individual packets. Such reduction of run length is needed to reduce the possible points of breakdown, to facilitate threading, and to increase production. There has also developed a need to improve the manner in which the vertically sealed containers formed in the paper are opened just prior to entry of the filling spouts in order to insure positive opening and to prevent the spouts missing the containers. Experience with the apparatus and method disclosed in U.S. Pat. No. 3,631,903 has also revealed the need for maintaining registry between the formed containers and other moving components and a need for improvement in the horizontal sealing. While registration apparatus is well known, it has never been applied in a practical way with a filling apparatus of the type described in U.S. Pat. No. 3,631,903. Finally, there has proven to be a need for improving the spout shape and for providing a more positive method of feeding the material, e.g., sugar, into the dispensing drum and maintaining level control.